Controlling fluid pressure is needed and advantageous in many industries and environments. One such environment relates to controlling pressure in a wellbore during a drilling or another oilfield process.
Wells are drilled on land and in marine environments for a variety of exploratory and extractive purposes. Due to the variety of purposes, the conditions experienced while producing the wells also vary greatly. The particular conditions include changes in temperature, pressure, subterranean fluids, and formations, among other variables. Managed Pressure Drilling (“MPD”) is used to ensure the pressure within the wellbore is maintained within predetermined limits relative to the surrounding formation pressure. The formation pressure may change during drilling of the wellbore. The applied fluid pressure by the drilling system is increased or decreased as necessary to keep the wellbore pressure within the desired limits. Chokes, for example, may be used to maintain the wellbore pressure within the predetermined limits.